The Doctor, Polly, Ben and Jamie find themselves on a moonbase in the year
2070. Housed there is the Gravitron, a device which controls the Earth's
weather. But a suspicious plague has erupted among the base's crew, and
the Gravitron has been experiencing mysterious faults. The moonbase chief
suspects the time travellers are responsible, but the Doctor soon realises
that his old foes, the Cybermen, are covertly at work in a new attempt to
invade the Earth.

Production

The two stories originally set to follow Patrick Troughton's debut serial,
The Power Of The Daleks, were The Underwater Menace and The Highlanders. When it was determined that The Underwater Menace could not be feasibly made
on a Doctor Who budget, it was dropped from the schedule; The Highlanders was moved up one slot and
William Emms' “The Imps” was added to the schedule as the
Second Doctor's new third adventure. However, Emms fell ill, preventing
him from accomplishing necessary rewrites on “The Imps”. An
amended The Underwater Menace therefore
returned to the schedule in its place, with “The Imps” now
intended to follow it.

Meanwhile, the Cybermen had debuted on Doctor Who in The Tenth Planet, the final serial to feature
William Hartnell's Doctor. The monsters, created by Kit Pedler and story
editor Gerry Davis, had proved very popular, and producer Innes Lloyd
hoped that they might make worthy successors to the Daleks, who were now
largely viewed as old hat. Shortly after The Tenth
Planet finished production, Lloyd approached Pedler about
developing a new storyline involving the Cybermen, this time set on the
Moon to tap into the interest in the burgeoning space race between the
United States and the Soviet Union. To save on costs, Davis wanted the new
adventure to take place predominantly on one large set, with just a
handful of smaller subsidiary sets and a limited supporting cast; this
would be a formula often repeated in forthcoming seasons.

To save on costs, Gerry Davis wanted the adventure to take
place mostly on one large set, with just a handful of smaller sets

“The Return Of The Cybermen” was commissioned on November
18th, 1966. At about the same time, Pedler was made aware that he would
have to incorporate the new character of Jamie into his storyline, Jamie
having been a last-minute addition to the regular cast during production
on The Highlanders. Pedler sought to minimise
Jamie's impact on “The Return Of The Cybermen” by leaving him
unconscious for much of its length, but Davis -- who worked closely with
Pedler on the scripts -- would later expand the new companion's role
somewhat. At this stage, the Cybermen had personal names, as had been the
case in The Tenth Planet, with the lead
Cyberman known as Tarn (a name Pedler had also used in the earlier serial)
or Kron. Eventually, any such references were eliminated, and the nameless
status of the Cybermen would become the norm in all their future
appearances.

Meanwhile, in mid-December, “The Imps” was dropped from the
schedule; “The Return Of The Cybermen” took its place as
Serial HH. Soon thereafter, it underwent a name change to The
Moonbase. (“The Imps” would shortly be abandoned
altogether on January 10th, 1967.) It was known at this time that -- due
to a break in production at the end of December because of the holiday
season -- episodes of Doctor Who would soon be aired just one week
after production, a precarious situation at best. On December 1st, the
possibility of holding back broadcast of The Moonbase by a week was
considered, to restore the delay between recording and transmission to two
weeks, but this did not come to pass. On January 10th, the option on
Frazer Hines' contract for Serial HH was taken up. At about the same time,
Peter Bryant -- who had recently begun assisting Davis in the story
editor's position -- briefly took over as producer when Lloyd embarked on
a week's holidays.

The director assigned to The Moonbase was Morris Barry, a former
repertory theatre actor who had joined the BBC as a floor manager in the
mid-Fifties. Barry had been promoted to director by the end of that
decade, working on programmes including Z Cars, and had also
produced series such as Compact and 199 Park Lane; Davis had
served as story editor on the latter.

Sandra Reid redesigned the Cybermen to look more robotic
and streamlined

Filming at the Ealing Television Film Studios took place from January 17th
to 20th, with the scenes on the Moon's surface being the major concern.
This saw the debut of the new-look Cybermen, who had been thoroughly
reimagined by Sandra Reid. Reid had also created their original appearance
for The Tenth Planet. The production team
wanted the monsters to look more robotic and streamlined, and so Reid
crafted three alternative designs from which Lloyd and Barry made their
selection. Amongst the extras playing Cybermen who joined the production
on January 19th was John Levine who (under the slightly altered surname
“Levene”) would play recurring character Sergeant Benton in
Doctor Who in the Seventies.

During filming, a small problem arose from the decision to change Benoit's
surname from Jules to Roget: the name plate for actor Andre Maranne's
outfit had already been prepared bearing the initial ‘J’, and
there was no way to change it in a timely manner. To compensate, Maranne
was given a neckerchief to wear to cover the offending letter.

As usual, each episode of The Moonbase was taped in order on
Saturdays, beginning on February 4th. The venue for the first three
episodes was Doctor Who's regular studio home of Riverside 1. A
potentially severe accident occurred during camera rehearsals for part one
when the Gravitron prop collapsed just seconds after Troughton had passed
underneath it. Fortunately, the actor was not injured and the prop was
rebuilt before recording began. Episode three, taped on the 18th, overran
its allotted timeslot, forcing the deletion of a scene involving Hobson,
Benoit and a Cyberman. This would have revealed that these Cybermen had
left Mondas prior to its destruction in The Tenth
Planet and had settled on the planet Telos.

Much to Innes Lloyd's disappointment, with part four,
Doctor Who returned to the antiquated Lime
Grove Studios

Much to Lloyd's disappointment, part three marked the end of Doctor
Who's residence at Riverside Studios. The series would now move back
to the more cramped and antiquated confines of Lime Grove D, which had
housed Doctor Who during its first year in production. Lloyd
complained that the inferior quality of Lime Grove's facilities might make
it necessary to transfer all film material onto videotape prior to
editing. Doctor Who returned to Lime Grove D on February 25th to
record episode four; the final scene of this installment had been recorded
by director John Davies on the 17th at Ealing as part of filming for the
next serial, The Macra Terror.

The difficulties of working in Lime Grove D immediately became apparent
when, reviewing the part four footage the next week, Barry discovered
that the sound equipment had picked up some of the chatter from the floor
manager's headphones. Since there was no possibility of the episode being
rerecorded due to the need to broadcast it the following Saturday, Barry
was forced to edit out this “talkback” as much as possible.
Nonetheless, the return of the Cybermen was judged to be a success, and by
the start of March, plans were already afoot to bring them back again for
Season Five.